WASHINGTON - At a forum hosted by the American Civil Liberties Union, prominent conservatives today echoed concerns held by many on the left and the right about recent security measures that go beyond combating terrorism, infringe on civil liberties and are of questionable effectiveness in meeting the threats facing a post-9/11 America.

The discussion this morning represented the first time organizations from the left and right in Washington have come together publicly to discuss their growing common ground on civil liberties concerns in the post-9/11 world.

""The broad principled concern shown today suggests that Congress must reconsider some of the measures that were adopted with little debate in the weeks after the terrorist attacks,"" said Laura W. Murphy, Director of the ACLU Washington Legislative Office, who moderated the discussion. ""We are unanimous in our strong belief that Congress must treat with deep skepticism any additional requests for new intelligence gathering powers.""

Other participants in today's forum - a ""Discussion with Conservatives: State of Civil Liberties Post 9/11"" - were David Keene, President of the American Conservative Union; Grover Norquist, President of Americans for Tax Reform; Lori Waters, Executive Director for the Eagle Forum, and Bob Barr, former Republican Congressman.

Of the utmost concern to the group was the recently leaked draft legislative proposal known as PATRIOT II, the ""Total Information Awareness"" program, the Department of Defense's cyber-surveillance system, and the Computer Assisted Passenger Pre-Screening System (CAPPS II), soon to be implemented by the Transportation Security Administration.

All three initiatives worry privacy advocates because they break down crucial checks and balances on surveillance and law enforcement powers in place to protect law-abiding citizens from repressive government actions.

For several months now, the right and the left have united in opposition to the implementation of both the Total Information Awareness and CAPPS II system, saying that both are based on the flawed and dangerous intelligence idea that to catch terrorists, the government needs to spy on people who have done nothing wrong.

Provisions in the PATRIOT II proposal that would permit warrantless searches, broad asset forfeiture with negligible judicial review, secret arrests and stripping people of their citizenship even if they had no intention of supporting terrorism all trouble the Constitution-hawks who took part in today's event.

""Many of these measures would be analogous to allowing police officers total access to the credit card transactions of every law-abiding resident of a particular state in their search for a robber using a stolen VISA,"" former Congressman Barr said. ""Not only is this logistically tough - it's an extreme privacy invasion.""